On a snowy February day in 1993, a rented van carrying a bomb was driven into one of the World Trade Center's public parking garages and parked. After lighting the bomb's fuse, the van's driver and a passenger escaped into a car driven by another conspirator. The bomb went off a short time later, causing death, destruction, a mass evacuation and a sense of terror that has reverberated throughout big building security ever since. The terrorists succeeded, in part, because New York's World Trade Center was then an open-building environment typical of most public office complexes in America.

Today, before anyone can gain access to the World Trade Center's sub-grade parking garages, they must meet a host of security requirements and pass through a system of access control devices that makes extremely unlikely the recurrence of a blast such as the one that rocked the complex, killing six people and injuring 1,000.

Now, only monthly tenant parking is allowed in the underground garages, and drivers must "register" along with their vehicles. They can enter and exit the parking lots at six strictly controlled access points, where their presence is:

And that's just for starters. If a vehicle stalls, or fails to arrive at its assigned parking space within a predetermined amount of time, a special program will alert the main security command station as well as satellite command centers.

If the vehicle proceeds right to its assigned parking area, it will pass still a third security station and another EVI reader that regulates parking lot capacity loading and vehicle reallocation when one lot is full.

If the security system picks up an irregularity, the vehicle will not be able to enter or exit the underground parking complex.

Would-be terrorists will find it no easier to gain access by foot. Tenants and employees have to put their photo ID/proximity cards on turnstiles to gain entrance to the four buildings in the complex - the Twin Towers and Buildings 4 and 5 - managed by the Port Authority of New York and New Jersey. All visitors must wait to be issued time- and date-sensitive visitor badges with magnetic stripes that indicate clearly which floors or buildings they are authorized to enter.

Not even the mail chutes are easily accessible; they have been fitted with narrow steel slots to preclude the depositing of large packages and bulky letters that could contain bombs.

Sitting on 16 square acres in downtown Manhattan at the foot of the Hudson River, the World Trade Center complex - the largest commercial office complex in the world - consists of the Twin Towers and five additional buildings, including the Marriott Hotel and the U.S. Customs Building. Towers 1 and 2 and Buildings 4 and 5 are protected by the Port Authority of New York and New Jersey's partially completed security plan to install an integrated vehicle and lobby access control, intercom and CCTV security system. The complex has 30,000 to 40,000 tenants and employees and admits thousands of visitors each day.

According to Hermon J. Banks, manager, life safety and security programs, "It's like a small city."

That city's calm was shattered on February 26, 1993, when the terrorists' bomb exploded on the Basement 2 level at 12:18 p.m., disintegrating the concrete floors of the B1 and B2 levels and creating a crater that consumed five underground floors, instantly setting more than 200 cars ablaze, and releasing smoke that, within minutes, was drawn up through elevator shafts to the top of both 110-story Twin Towers. More than 30,000 employees and thousands of visitors had to be evacuated, and the rescue operation lasted 12 hours. In addition to six fatalities, the loss of an unborn child and a thousand injuries, the property damage was estimated at more than $300 million.

The towers and their 100-plus acres of office space were fully reoccupied a mere six weeks later due to a much heralded effort by scores of engineers and employees. But what has taken longer than repairing and reoccupying the damaged building has been revamping and reinventing its security infrastructure. Never again

Despite its size, strength and sophistication, the World Trade Center did not have an automated access control system before the blast. Most public office buildings in America do not. But that trend is likely to change, now that the "It can't happen here" mindset has been replaced with the determination that "It won't happen here again" - at least not at the World Trade Center.

Once time had begun to dull the shock, grief and sadness of the blast and its tragic consequences, Port Authority security and safety personnel found that pride, sensitivity and a singleness of purpose had become part of their routine. No breach of security or safety was too small to respond to instantly or to take seriously. When a uniformed security officer turns someone away from the visitor's desk because he lacks proper credentials, she does so with a clear, courteous explanation, but without apology.

When her supervisor directs visitors lined up behind a plant-filled barricade to the next available desk where their credentials will be checked, he does so with the authority of a traffic cop standing in the middle of a major thoroughfare. People, not cars, are passing through, but the safety of the small city depends on their being deployed according to strict procedures.

"After the bombing, we had the top security consultants in the nation, Kroll Associates, do a complete security analysis for us, and we followed their recommendations," says Douglas G. Karpiloff, program manager, security systems for the WTC. A 26-year veteran of the Port Authority, Karpiloff, a Certified Protection Professional, was general manager of tenant services after the bomb went off. He is responsible for the overall facility management of the $50 million security improvement program: $15 million in completed interim improvements and $35 million for permanent improvements, from the 250 multi-ton perimeter planters that prevent vehicles from crashing into the buildings, to the network of fiber optics and copper that will connect the redundant PCs and their multi-task, multi-user operating system to the lobby, parking and perimeter access control systems, alarms, intercom and CCTV systems.

Karpiloff is also under contract to the Federal Protective Service and has completed an overall threat assessment and security master plan for the Ronald Reagan Center, the largest building complex in Washington, D.C., after the Pentagon. He has developed restrictive parking policies for other sensitive government buildings in Washington, and he helped major building owners in Denver upgrade their security in preparation for the Oklahoma City bombing trial.

He is a man with a mission who speaks with pride of the innovations and subtleties of the WTC's security system.

"We've developed a real team approach to security here," he explains. "Our outstanding engineering department, with Fred Ng and Paul Salvatore, oversees final design and field construction with support from their consultant, Analytical Systems Engineering Corp. Our information systems department, with Vic Guarnera, works on the software systems side of the house. My second-in-command, George Tabeek, and I concentrate on delivering a working system that balances security and tenant needs. Hermon Banks focuses on day-to-day operations, supported by Mike Hurley, manager of fire prevention, life safety and emergency services."

Fire prevention and life safety Each of the four buildings the Port Authority oversees has a stand-alone Class E Pyrotronics fire safety system with its own PC-based file server and operating system. The system controls the complex's smoke detectors, which, upon sensing smoke, emit a small electronic signal that is sent to a local control device, or alarm, which transmits a coded signal to the computer that tells fire officials where to respond. The signals are sent to on- and off-site alarm monitoring stations.

Hurley, a 17-year veteran of the Port Authority, is responsible for all aspects of fire prevention, life safety, emergency preparedness, fire command, code enforcement, training and fire department liaison.

"The fire system is designed to provide us with an alarm from the individual smoke detectors that automatically transmit to the fire command stations staffed by deputy fire safety directors," says Hurley. "They then notify emergency response personnel in the building, as well as the New York City Fire Department. Each smoke detector and sprinkler head is assigned an 'address' so we know exactly where the alarm originates from. There are satellite fire command stations in each of the buildings."

According to Hurley, the Port Authority and WTC are unique because they have their own police force and emergency response personnel, who serve as an in-house fire brigade. The fire brigade has pre-positioned crash carts with Scott air packs and fire fighting equipment so they can begin fire suppression activities even before the fire department arrives.

The fire system includes a PC, associated software, a board that identifies manual pull stations for each floor and a public address system. The alarms, smoke detectors, sprinklers and P/A systems are all integrated, and each of the four buildings has a totally independent system.

"Our design philosophy is that no single event will be able to take us down as a facility," says Hurley.

To avoid the type of total power outage that occurred during the 1993 bombing, backup life safety and power systems have been put in place. A new operations center will contain backup for the security command center, and the security command center will contain backup for operations center functions, including alarms, intercoms and elevator controls.

"All the stairwells now have battery-pack lighting and photoluminescent paint on the floor and hand-rails," says Hurley. "Every door sign is photoluminescent and also in Braille, exceeding city requirements. At the minimum, if our power went out and all backups failed, the stairways would glow in the dark."

Every effort has been made, however, to ensure that all power will not go out again, as it did during the bombing, leaving the complex in darkness.

"We have our primary power source, our emergency diesel generators and our battery packs," says Karpiloff, "but we have something new as well: We've run a power line through the PATH system from New Jersey to New York to use as a backup for electricity. We are the only commercial building in New York City with such a system."

The parking access control system The parking access control system at the WTC was manufactured and installed by Ensec Inc., Boca Raton, Fla. The Enworks EN2000 system has a redundant host configuration and supports full function work stations. It is designed to integrate vehicle and driver access control, alarm monitoring and the parking security intercom.

HID proximity card readers and Amtech Smart Pass Readers read drivers' proximity cards and Auto Vehicle Identification (AVI) tags on car windshields. The system is meant to be "failsafe," ensuring that both the driver and the vehicle together are authorized to gain entry to the parking garage, a feature about which Karpiloff is particularly excited.

"The person and the vehicle are enrolled as pairs," he explains. "The driver is registered for a particular vehicle. When the proximity card reader and the AVI reader information match, the system opens the gate and allows the vehicle to enter from the street. Once the vehicle and driver are in the environment, we check further to make sure they have arrived at the assigned location."

But before the vehicle even enters the parking garage, vehicle ground loop detectors - loops of signal wire that set up a radio field - pick up the vehicle's presence and work in conjunction with the AVI and proximity card readers to transfer relevant information to that particular parking lot entrance.

Also included in the system is a series of Delta Scientific Corp. anti-ram hydraulic barriers. When the system allows entry, the gate arm goes up, and the anti-ram devices go down below the surface. If a vehicle is denied access, the anti-ram barriers go up, and the gate arm does not allow entry.

Separate remote processors for alarms are integrated with the access control system and cause alarms to go off if a security breach is picked up.

"The remote processors support all the information necessary to control the vehicle and the driver, to handle any duress features we have installed, along with some 25 exceptions. They can handle more than 2,500 cardholders," explains Vic Guarnera, project manager for the information services department (ISD).

"In addition, all the alarms are sent back to a workstation, which is attached to the main file server. The person at the workstation responds to and analyzes the alarms, determines appropriate action, and may communicate with the person at the access or alarm point."

There are manned security booths at the entrance/exit points as well. "We have six ramps at which entry and exit can be reversed," says Guarnera, "and guards at those ramps provide extra security for the sub-grade parking area. Any alarm that sounds is displayed on the ramp monitor at the guard's booth as well as on a display event monitor in the parking security office where the clerk enrolls new parkers and vehicles or changes access requirements."

Remote processors for access control and alarms at the parking garages, and workstations at the guard booths, parking office, visitor centers and security command center and other areas, are connected to a main, redundant file server.

Guarnera says the Port Authority's ultimate objective for integration of the security system is to have the lobby and vehicle access control systems integrated together. That will first be accomplished by an interface between the parking and turnstile systems, and at a later date, they will be fully integrated.

"We are using an off-the-shelf environment as much as possible for the permanent operating system," he says. "It must be robust enough to support a system of this size with more than 100 turnstiles, 250 controlled and monitored doors and hundreds of CCTV cameras. It must be able to handle a database that reflects the 45,000 tenant/employee volume we have plus 5,000 to 6,000 visitors per day."

The system integration will allow the two systems to share information on a full-time, real-time basis by way of a channel or dedicated communications linkage. Alarms from the parking system will be integrated with alarms from the turnstile access control system, and one proximity card will be used for both parking and turnstile access control.

The CCTV system Construction is well under way on the installation of an expanded, upgraded CCTV system of covert and overt pan/tilt/zoom, alarm-point cameras. The camera system's American Dynamics matrix switchers will be able to function alone and will also be integrated with the PC computer system.

"We're putting in an upgraded, high-resolution, color CCTV system," says Karpiloff. "The parking entrances and exits and the visitor center areas are already under continuous CCTV monitoring, both covert and overt.

"We believe the expanded system will represent the first time a commercial building in the United States will have a detection system to pick up stopped vehicles at its perimeter. If a vehicle is parked and not moving, we will detect the lack of movement, which will activate the CCTV camera to point to exactly where the vehicle has been detected and record and transmit the information to command stations that can instantly dispatch police."

Karpiloff further explains that, while most CCTV systems are driven by the fact that something is taking place, i.e., a "positive" event, it was more difficult to locate hardware and software that would encompass "negative" events such as stationary vehicles. The video transmissions processed by the program will be wired directly into the multiplex switchers.

Apart from that unique feature of picking up "non-events" in the parking areas, the system generally will be action-activated.

"The camera may be in place but may not record unless something happens, such as a car driving through an area or a person walking past the camera, an event. All the perimeter security is set up like that," notes Hermon Banks. "We have found that guards will pay attention to the CCTV monitors far more effectively with this type of system than if they are simply on all the time."

Cameras, he says, are placed in critical locations within the complex, such as machine rooms, computer areas, visitor areas and other sensitive locations.

"High-powered, 400-line SVHS video recorders support the CCTV system," Karpiloff adds. "If someone tries to force a door or a gate, a video buffering feature, which stores images for a certain period of time, will have recorded the person even before he or she tries to force entry."

Visitor center, lobby and tenant access control Banks manages the complex's security programs, which include a contract guard force of more than 300 people. He has held his position for nearly three years, and was chosen after a nationwide search. A veteran of more than 21 years with the New York City Police Department, Banks went on to the New York City Health and Hospitals Corp.'s security division. As its assistant inspector general, he trained its police force, chaired its safety committee and managed life safety, among other responsibilities. Banks believes his experience with both security and life safety was a strong factor in his being chosen for the WTC job. The lobby access control system is not yet completely automated, but Banks points out that visitors must approach one of the visitor's desks in each of the four buildings, show their identification, and explain where they're from and who they're visiting. The present system records their destination, the date and time arrived, and archives the information for a year.

"I get a printout monthly of every visitor by tower, tenant and category - announced, unannounced and courier," says Banks. "I can recall the information at any time. In fact, I just had a request for information on a visitor from last spring, and someone is searching the database as we speak."

>From a PC in his office, Banks monitors the visitor's desks for managerial and security information such as how long it takes the operators to process visitors. He also examines reports generated by the database.

Tenants, employees, long-term visitors and contractors are using color-coded ID cards until the lobby access control system is fully automated.

Long-term visitors are issued a Polaroid ID3000 system card that is examined by guards upon entry and, when held under special lighting, reveals if there has been tampering.

"All tenant contact names are in a central database and we have issued photo IDs to tenants, employees, long-term visitors and contractors," says Karpiloff.

The lobby access control system will include Perey turnstiles. New, Motorola Indala proximity cards will be issued, which will be read by Motorola Indala readers when the holder places them just above the turnstiles. Visitors will be issued plastic photo ID cards with magnetic stripes that they will swipe through readers.

The contractors for the permanent security system are E.J. Electric and Electronic Systems Associates, both of New York. Securacom, Woodcliff Lakes, N.J., is responsible for system integration.

Also, ASSA of Brooklyn, N.Y., is installing a new key system. The UL437-approved, high-security cylinders and keys contain a proprietary keyway. Each cylinder and key has a bar code imbedded in it. A Qualisoft software control system for issuance of the keys includes remote, hand-held and fixed-location scanners that scan employee ID cards and then scan the key to make sure the key and the person match. All key rings are also weighed before daily distribution to make sure they have not been tampered with.

"We are re-keying all tenant premises in the complex, and all electrical, mechanical, structural and base building systems," says Karpiloff. "Bob Schutz, our chief locksmith, has the unenviable task of leading his men in the massive job of installing 8,000 new cylinders and issuing more than 75,000 new keys." Since the bombing, little has stayed the same at the World Trade Center. Before that devastating day, it was an open complex, closed only on weekends. Today, it is a closed complex, since eyes have been opened to the importance of access control.